Add AGP GART implementation

src/video/agpgart.c

@@ -0,0 +1,193 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box distribution.
+ *
+ *		AGP Graphics Address Remapping Table remapping emulation.
+ *
+ *
+ *
+ * Authors:	RichardG, <richardg867@gmail.com>
+ *
+ *		Copyright 2021 RichardG.
+ */
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#define HAVE_STDARG_H
+#include <86box/86box.h>
+#include <86box/device.h>
+#include <86box/mem.h>
+
+
+typedef struct {
+    int		aperture_enable;
+    uint32_t	aperture_base, aperture_size, aperture_mask, gart_base;
+    mem_mapping_t aperture_mapping;
+} agpgart_t;
+
+#define ENABLE_AGPGART_LOG 1
+#ifdef ENABLE_AGPGART_LOG
+int agpgart_do_log = ENABLE_AGPGART_LOG;
+
+static void
+agpgart_log(const char *fmt, ...)
+{
+    va_list ap;
+
+    if (agpgart_do_log) {
+	va_start(ap, fmt);
+	pclog_ex(fmt, ap);
+	va_end(ap);
+    }
+}
+#else
+#define agpgart_log(fmt, ...)
+#endif
+
+
+void
+agpgart_set_aperture(void *handle, uint32_t base, uint32_t size, int enable)
+{
+    agpgart_t *dev = (agpgart_t *) handle;
+
+    agpgart_log("AGP GART: set_aperture(%08X, %d, %d)\n", base, size, enable);
+
+    /* Disable old aperture mapping. */
+    mem_mapping_disable(&dev->aperture_mapping);
+
+    /* Set new aperture base address, size and mask. */
+    dev->aperture_base = base;
+    dev->aperture_size = size;
+    dev->aperture_mask = size - 1;
+
+    /* Enable new aperture mapping if requested. */
+    if (dev->aperture_base && dev->aperture_size && dev->aperture_enable) {
+	mem_mapping_set_addr(&dev->aperture_mapping, dev->aperture_base, dev->aperture_size);
+	mem_mapping_enable(&dev->aperture_mapping);
+    }
+}
+
+
+void
+agpgart_set_gart(void *handle, uint32_t base)
+{
+    agpgart_t *dev = (agpgart_t *) handle;
+
+    agpgart_log("AGP GART: set_gart(%08X)\n", base);
+
+    /* Set GART base address. */
+    dev->gart_base = base;
+}
+
+
+static uint32_t
+agpgart_translate(uint32_t addr, agpgart_t *dev)
+{
+    /* Extract the bits we care about. */
+    addr &= dev->aperture_mask;
+
+    /* Get the GART pointer for this page. */
+    register uint32_t gart_ptr = mem_readl_phys(dev->gart_base + ((addr >> 10) & 0xfffffffc)) & 0xfffff000;
+
+    /* Return remapped address with the page offset. */
+    return gart_ptr + (addr & 0x00000fff);
+}
+
+
+static uint8_t
+agpgart_aperture_readb(uint32_t addr, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    return mem_readb_phys(agpgart_translate(addr, dev));
+}
+
+
+static uint16_t
+agpgart_aperture_readw(uint32_t addr, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    return mem_readw_phys(agpgart_translate(addr, dev));
+}
+
+
+static uint32_t
+agpgart_aperture_readl(uint32_t addr, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    return mem_readl_phys(agpgart_translate(addr, dev));
+}
+
+
+static void
+agpgart_aperture_writeb(uint32_t addr, uint8_t val, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    mem_writeb_phys(agpgart_translate(addr, dev), val);
+}
+
+
+static void
+agpgart_aperture_writew(uint32_t addr, uint16_t val, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    mem_writew_phys(agpgart_translate(addr, dev), val);
+}
+
+
+static void
+agpgart_aperture_writel(uint32_t addr, uint32_t val, void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+    mem_writel_phys(agpgart_translate(addr, dev), val);
+}
+
+
+static void *
+agpgart_init(const device_t *info)
+{
+    agpgart_t *dev = malloc(sizeof(agpgart_t));
+    memset(dev, 0, sizeof(agpgart_t));
+
+    agpgart_log("AGP GART: init()\n");
+
+    /* Create aperture mapping. */
+    mem_mapping_add(&dev->aperture_mapping, 0, 0,
+		    agpgart_aperture_readb, agpgart_aperture_readw, agpgart_aperture_readl,
+		    agpgart_aperture_writeb, agpgart_aperture_writew, agpgart_aperture_writel,
+		    NULL, MEM_MAPPING_EXTERNAL, dev);
+
+    return dev;
+}
+
+
+static void
+agpgart_close(void *priv)
+{
+    agpgart_t *dev = (agpgart_t *) priv;
+
+    agpgart_log("AGP GART: close()\n");
+
+    /* Disable aperture. */
+    mem_mapping_disable(&dev->aperture_mapping);
+
+    free(dev);
+}
+
+
+const device_t agpgart_device =
+{
+    "AGP Graphics Address Remapping Table",
+    DEVICE_PCI,
+    0,
+    agpgart_init, agpgart_close, NULL,
+    { NULL },
+    NULL,
+    NULL,
+    NULL
+};